<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<body>
<script>
  function readableURL(url) {
    return url.replace(/\n/g, "\\n").replace(/\r/g, "\\r").replace(/\t/g, "\\t");
  }

  // For each of the following tests, we'll inject a frame containing the HTML we'd like to poke at
  // as a `srcdoc` attribute. Because we're injecting markup via `srcdoc`, we need to entity-escape
  // the content we'd like to treat as "raw" (e.g. `\n` => `&#10;`, `<` => `&lt;`), and
  // double-escape the "escaped" content.
  var rawBrace = "&lt;";
  var escapedBrace = "&amp;lt;";
  var doubleEscapedBrace = "&amp;amp;lt;";
  var rawNewline = "&#10;";
  var escapedNewline = "&amp;#10;";
  // doubleEscapedNewline is used inside a data URI, and so must have its '#' escaped.
  var doubleEscapedNewline = "&amp;amp;%2310;";

  function appendFrameAndGetElement(test, frame) {
    return new Promise((resolve, reject) => {
      frame.onload = test.step_func(_ => {
        frame.onload = null;
        resolve(frame.contentDocument.querySelector('#dangling'));
      });
      document.body.appendChild(frame);
    });
  }

  function assert_img_loaded(test, frame) {
    appendFrameAndGetElement(test, frame)
      .then(test.step_func_done(img => {
        assert_equals(img.naturalHeight, 1, "Height");
        frame.remove();
      }));
  }

  function assert_img_not_loaded(test, frame) {
    appendFrameAndGetElement(test, frame)
      .then(test.step_func_done(img => {
        assert_equals(img.naturalHeight, 0, "Height");
        assert_equals(img.naturalWidth, 0, "Width");
      }));
  }

  function assert_nested_img_not_loaded(test, frame) {
    window.addEventListener('message', test.step_func(e => {
      if (e.source != frame.contentWindow)
        return;

      assert_equals(e.data, 'error');
      test.done();
    }));
    appendFrameAndGetElement(test, frame);
  }

  function assert_nested_img_loaded(test, frame) {
    window.addEventListener('message', test.step_func(e => {
      if (e.source != frame.contentWindow)
        return;

      assert_equals(e.data, 'loaded');
      test.done();
    }));
    appendFrameAndGetElement(test, frame);
  }

  function createFrame(markup) {
    var i = document.createElement('iframe');
    i.srcdoc = `${markup}sekrit`;
    return i;
  }

  // Subresource requests:
  [
    // Data URLs don't themselves trigger blocking:
    `<img id="dangling" src="">`,
    `<img id="dangling" src="data:image/png;base64,${rawNewline}iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=">`,
    `<img id="dangling" src="${rawNewline}VBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=">`,

    // Data URLs with visual structure don't trigger blocking
    `<img id="dangling" src="data:image/svg+xml;utf8,
      <svg width='1' height='1' xmlns='http://www.w3.org/2000/svg'>
        <rect width='100%' height='100%' fill='rebeccapurple'/>
        <rect x='10%' y='10%' width='80%' height='80%' fill='lightgreen'/>
      </svg>">`
  ].forEach(markup => {
    async_test(t => {
      var i = createFrame(`${markup} <element attr="" another=''>`);
      assert_img_loaded(t, i);
    }, readableURL(markup));
  });

  // Nested subresource requests:
  //
  // The following tests load a given HTML string into `<iframe srcdoc="...">`, so we'll
  // end up with a frame with an ID of `dangling` inside the srcdoc frame. That frame's
  // `src` is a `data:` URL that resolves to an HTML document containing an `<img>`. The
  // error/load handlers on that image are piped back up to the top-level document to
  // determine whether the tests' expectations were met. *phew*

  // Allowed:
  [
     // Just a newline:
     `<iframe id="dangling"
        src="data:text/html,
            <img
              onload='window.parent.postMessage(&quot;loaded&quot;, &quot;*&quot;);'
              onerror='window.parent.postMessage(&quot;error&quot;, &quot;*&quot;);'
              src='http://{{host}}:{{ports[http][0]}}/images/gr${rawNewline}een-256x256.png'>
        ">
     </iframe>`,

     // Just a brace:
     `<iframe id="dangling"
        src="data:text/html,
            <img
              onload='window.parent.postMessage(&quot;loaded&quot;, &quot;*&quot;);'
              onerror='window.parent.postMessage(&quot;error&quot;, &quot;*&quot;);'
              src='http://{{host}}:{{ports[http][0]}}/images/green-256x256.png?${rawBrace}'>
        ">
     </iframe>`,

     // Newline and escaped brace.
     `<iframe id="dangling"
        src="data:text/html,
            <img
              onload='window.parent.postMessage(&quot;loaded&quot;, &quot;*&quot;);'
              onerror='window.parent.postMessage(&quot;error&quot;, &quot;*&quot;);'
              src='http://{{host}}:{{ports[http][0]}}/images/gr${rawNewline}een-256x256.png?${doubleEscapedBrace}'>
        ">
     </iframe>`,

     // Brace and escaped newline:
     `<iframe id="dangling"
        src="data:text/html,
            <img
              onload='window.parent.postMessage(&quot;loaded&quot;, &quot;*&quot;);'
              onerror='window.parent.postMessage(&quot;error&quot;, &quot;*&quot;);'
              src='http://{{host}}:{{ports[http][0]}}/images/green-256x256.png?${doubleEscapedNewline}${rawBrace}'>
        ">
     </iframe>`,
  ].forEach(markup => {
    async_test(t => {
      var i = createFrame(`
        <script>
          // Repeat the message so that the parent can track this frame as the source.
          window.onmessage = e => window.parent.postMessage(e.data, '*');
        </scr`+`ipt>
        ${markup}
      `);
      assert_nested_img_loaded(t, i);
    }, readableURL(markup));
  });

  // Nested requests that should fail:
  [
     // Newline and brace:
     `<iframe id="dangling"
        src="data:text/html,
            <img
              onload='window.parent.postMessage(&quot;loaded&quot;, &quot;*&quot;);'
              onerror='window.parent.postMessage(&quot;error&quot;, &quot;*&quot;);'
              src='http://{{host}}:{{ports[http][0]}}/images/gr${rawNewline}een-256x256.png?${rawBrace}'>
        ">
     </iframe>`,

     // Leading whitespace:
     `<iframe id="dangling"
        src="     data:text/html,
            <img
              onload='window.parent.postMessage(&quot;loaded&quot;, &quot;*&quot;);'
              onerror='window.parent.postMessage(&quot;error&quot;, &quot;*&quot;);'
              src='http://{{host}}:{{ports[http][0]}}/images/gr${rawNewline}een-256x256.png?${rawBrace}'>
        ">
     </iframe>`,

     // Leading newline:
     `<iframe id="dangling"
        src="\ndata:text/html,
            <img
              onload='window.parent.postMessage(&quot;loaded&quot;, &quot;*&quot;);'
              onerror='window.parent.postMessage(&quot;error&quot;, &quot;*&quot;);'
              src='http://{{host}}:{{ports[http][0]}}/images/gr${rawNewline}een-256x256.png?${rawBrace}'>
        ">
     </iframe>`,
     `<iframe id="dangling"
        src="${rawNewline}data:text/html,
            <img
              onload='window.parent.postMessage(&quot;loaded&quot;, &quot;*&quot;);'
              onerror='window.parent.postMessage(&quot;error&quot;, &quot;*&quot;);'
              src='http://{{host}}:{{ports[http][0]}}/images/gr${rawNewline}een-256x256.png?${rawBrace}'>
        ">
     </iframe>`,

     // Leading tab:
     `<iframe id="dangling"
        src="\tdata:text/html,
            <img
              onload='window.parent.postMessage(&quot;loaded&quot;, &quot;*&quot;);'
              onerror='window.parent.postMessage(&quot;error&quot;, &quot;*&quot;);'
              src='http://{{host}}:{{ports[http][0]}}/images/gr${rawNewline}een-256x256.png?${rawBrace}'>
        ">
     </iframe>`,

     // Leading carrige return:
     `<iframe id="dangling"
        src="\rdata:text/html,
            <img
              onload='window.parent.postMessage(&quot;loaded&quot;, &quot;*&quot;);'
              onerror='window.parent.postMessage(&quot;error&quot;, &quot;*&quot;);'
              src='http://{{host}}:{{ports[http][0]}}/images/gr${rawNewline}een-256x256.png?${rawBrace}'>
        ">
     </iframe>`,
  ].forEach(markup => {
    async_test(t => {
      var i = createFrame(`
        <script>
          // Repeat the message so that the parent can track this frame as the source.
          window.onmessage = e => window.parent.postMessage(e.data, '*');
        </scr`+`ipt>
        ${markup}
      `);
      assert_nested_img_not_loaded(t, i);
    }, readableURL(markup));
  });
</script>
